This invention relates to an ice rink for ice skating in particular.
For making and maintaining an ice layer on an ice rink floor, the conventional method consists in laying a large number of freezing pipes on the rink floor and circulating a freezing medium or refrigerant such as brine, thereby forming and preserving an ice layer on the floor. To this effect, one ends of the freezing pipes are connected to a refrigerant supply header and the other ends of the pipes to a refrigerant return header. These supply and return headers are connected via delivery pipes and return pipes to a freezing unit. The freezing medium is circulated from the cooling unit going through the delivery pipe, the refrigerant supply header, the freezing pipe, the refrigerant return header and the return pipe and back to the cooling unit to complete the freezing cycle.
The freezing pipes may be installed widthwise of the rink, but in such case the number of the freezing tubes inevitably gets increased, causing installetion operation to be complicated with attendant high cost.
Therefore, it is generally preferred to lay the freezing tubes in the longitudinal direction of the rink. However, in laying the freezing pipes in this manner, it is practically difficult to prepare in advance the lengths of the freezing pipes corresponding to the overall rink length. Moreover, freezing pipes with such large length are inconvenient to handle or transport. When the pipes have their sections connected to one another at one or more joints, various disadvantages or problems may be accompanied with respect to the freezing effect. Above all, it must be considered an extremely long skating course is required under the international standards for an ice rink of the speed skating competition, and it is further required that such rink is provided with one or more curved sections, renderring it extremely difficult or impossible to install the freezing pipe having the length sufficient to cover the overall skating course. Incidentally to note, the standard double track for the speed skating ice rink is required to have two straight sections interconnected by two curved sections, these sections being respectively of the same length and placed symmetrically with respect to each other with the course length being 400 or 3331/3 meter and the inner radii of curvature of the curved sections being 29 meter. Therefore, in this speed skating rink, as shown in FIG. 1, the overall course is usually divided into four or eight spans or sections and the resulting junctions 3a to 3 d are provided with respective headers 4. A large number of freezing tubes 5 having the same length as that of the spans or sections 2a to 2d are laid in the spans 2a to 2d and the ends of these freezing tubes 5 are connected to the associated headers. In this case, the headers and the freezing tubes are usually mounted at the same relative height level on the rink floor. Since the header 4 is larger in diameter than the tube 5 and thus a larger amount of the freezing medium in allowed to pass therethrough per unit time, the water disposed above the header 4 is cooled more excessively than the water in any other area of the rink so that it is converted into a hardend ice to form an elevated ice layer. Thus, it was not possible to favorably obtain a smooth ice layer of good quality with uniform and homogeneous nature.
It is also known that the freezing pipes and headers are embedded inside of the concrete floor of ice rink for permanent use. In this case, however, the operation of pipe installation requires a great deal of time and labor with commensurate high costs. Moreover, it is impossible to dismount the freezing pipes or the headers when the rink is not in use. Also the cracks may be produced in the embedded portions of the floor over a prolonged time so that the headers may become corroded due to water intrusion with resulting refrigerant leakage, the rink being unable to be repaired even under such conditions.
The present invention has been acomplished to overcome the foregoing drawbacks of the prior art. It is an object of the present invention to provide an ice rink which is cost efficient and in which the freezing pipes can be either mounted or dismounted easily and the ice layer in the vicinity of the headers is kept from becoming too hard or too thick, so that the smooth ice layer of a highly uniform quality may be readily formed and maintained on the overall freezing area of the rink.